Radio inductance switch



Feb. -2, 1932. A. BROSNATCH 1,843,800-

RADIO INDUCTANCE SWITCH Filed March 19, 1950 \NVENTOR Hi5 ATTORNEY Patented Feb. 2, 1932 U N 'ITIEZD STATES ANDREW BBOSNATCH, OF CHICAGO, ILLINOIS RADIO INDUCTANGE SWITCH Application filed March '19, 1980. Serial No. 437,185.

This invention relates to certain novel improvements in a radio inductance switch and has for its principal object the provision of a device of this character Which will be highly efficient in use and economical in manufacture.

, It is among the objects of my invention to provide adevice-of the above named character which will-provide the operator of a radio receiving set with a means by which he will be enabled quickly and easily to switch from one coil of a certain meter wave length to another coil of a different wave length without the necessity of taking out a contact plug controlling the old wave length coil and plugging in a new contact as is now commonly necessary.

Another object of my invention is to provide a device which may be used as a selective resistance switch. I

A further object is to provide a device which can be used with double coil radio receiving sets connecting a different antenna coil and detector coil at the same time.

Other objects will appear hereinafter.

The invention consists in the novel combi nation and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings, showing the preferred form of construction and in which: p

v Fig. 1 is a rear plan view of the preferred embodiment of my invention;

Fig. 2 is a side view taken substantially on the line 22 on Fig. 1;

Fig. 3 is a sectional view taken substantially on the line 3-3 on Fig. 1;

I Fig. at is a perspective view showing in partthe movable discs and wiping brush contacts attached thereto; and

Fig. 5 is a perspective View, partly in section, of a modification of my invention.

I11 the drawings wherein the preferred 6111- bodiments of my invention are illustrated, 1 indicates a housing of suit-able insulating material and of substantially rectangular shape, the side and end portions thereof being secured together by means .of screws 2. 3 indicates a plurality of contact units supported by and passing through the housing 1. In Fig. 1, five sets of these contact units are shown, four units in each set. Two of these contact units in each set are connected by suitable conducting means (not shown) to the primary of an inductance coil (not shown) and two are connected to the secondary of the coil, the coil being of any desired wave length reception capacity. Or, these contact units 3 may be connected to suitable resistance units if the device is to be used in transmission. On the inner end of the contact posts-3 are suitable contact points 4 which are adapted to contact with movable contact members to be described hereinafter.

Attached to the housing 1 by screws or other suitable means are brush contact posts 5 arranged as shown in groups of four, two of each group leading by suitable conducting means (not shown) to the primary circuit of a radio receiving set while the other two lead to the secondary circuit of the receiving set. Or if the device is used in transmission these contact members 5 may be wired to permit of securing variable resistance through the inner parts to be described hereinafter, the contact posts 3, and suitable resistance units. Inserted through the walls of the housing 1 and supported by the said housing is a re volvable shaft 6 to one end of which is attached a machined knob 7 of the familiar type to permit movement of the shaft 6 as best shown in Figs. 2 and 3. The shaft 6 rotates in the housing 1 in a suitable journal 8, one or more washers 9, anda suitable journal 10, as shown in Figs. 2 and 3. Supported by and mounted on the revolvable shaft 6 are four metallic discs 11 insulated from each other by means of mica or other suitable insulating material 12. Holding 90 these discs 11 and the insulating material separating them in position on the shaft 6 are suitable nut and washer structures 1 and 14 and a coil spring 15 mounted on the J shaft 6 and interposed between the revolving set of discs and the wall of the housing at the side toward the knob 7, said spring 15 serving to prevent the nut 13 from becoming loose on the shaft 6 which would result in the Wiping contacts 16 failing to contact with contact post 3.

Attached to each of the revolvable discs 11 is a wiping brush arm 16 of resilient metal as best shown in Figs. 3 and 4.

In the operation of my device, when the revolvable shaft 6 is rotated by manipulation of the knob 7 the metallic discs 11 bring the four wiping brush arms 16, one attached to each disc, into individual contact engagement with one set of four of t 1e contact posts 3, two of which contact posts are attached to the primary of a coil adapted to the reception of radio waves of any desired wave length, the other two contact posts of the set of four being attached to the secondary of the coil. In this manner each one of the brush arms 16 engages one of the contact posts 3 in a group of four. The brushes 5 attached to one wall of the housing and having suitable binding posts or other connecting means attached thereto are made of resilient metal and each one is in permanent Wiping engagement with one of the revolvable discs 11. wo of these brushes 5 are, as already pointed out hereinbefore, connected by suitable conducting means to the primary circuit of a radio receiving set and two are connected with the secondary of the said receiving circuit. In this manner by bringing the four brushes 16 attached to the discs 11 into contact with a set of four of the contact posts 3 so that each one of the four revolvable brushes 16 is in contact with one of the four contact posts 3 in a group, the operator is enabled to tune in any wave length capable of reception by the coil attached to that particular set of four contact posts 3. By moving the revolvable discs 11 and attached brushes 16 a fifth of a turn as shown in Fig. 1 he is enabled to secure reception of a different range of wave lengths according to the reception capacity of the coil attached to that particular group of contact posts 3. In this manner the necessity of taking out a coil adapted to a certain range of wave length and plugging in another coil of the desired range of wave length is eliminated. 1

My invention as described above is especially adaptable to short wave radio receiv ing. Likewise, by suitable wiring as pointed out above, it may be used for short wave transmitting. As ii any coils as desired may be connected to my inductance switch or separate switches may be used for the antenna coil and the detectorcoil.

I may attach my inductance switch too in a manner so that the knob thereof is conveniently mounted on the front panel of the radio set. hen connections are made to coils that are of the desired receiving range the coils become a permanent part of the set and their removal is then not necessary.

It is understood that I do not limit myself to any definite number of groups of contact posts 3. In Fig. 1 I have shown five groups of these contact posts, four in each group, but it is understood that I may vary the number of groups of these within a wide range.

In Fig. 5 I have shown a modified form of construction of my invention which is adapted for use with a radio receiving apparatus in which two coils may be connected together and controlled simultaneously by means of the two sets of re olving discs 11, four discs in each set, and the wiping brushes 16 attached thereto, constituting eight wiping brushes. In this manner two sets of the stationary contacts 3, four in each set, may be engaged simultaneously by the two sets of wiping brushes 16. It is understood, however, that the number of discs 11, and the number of wiping brushes 16 attached thereto, may be varied within a wide range by increasing the size of the discs and the number of sets of stationary contacts 3.

While I have illustrated and described th preferred form of construction for carrying my invention into effect this is capable of variations and modifications without depar ing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth herein but desire. to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Let ters Patent is:

1. A switch comprising a rotative shaft, a plurality of spaced apart discs on and rotatable with said shaft and insulated from each other, a plurality of groups of stationary contacts and said groups being radially arranged about said shaft, a group of stationary brush contacts each having constant wiping engagement with one of said discs, and a wiping contact carried by each of said discs, said last named contacts adapted to have selective engagement as a group with any one of said first named groups of contacts upon rotation of said shaft.

2. In a device of the class described, a housing of substantially rectangular shape, a revolvable shaft projecting through said housing and supported by the walls of said housing, one end of said shaft projecting externally from said housing, means for securing said shaft in spaced relation in said housing along the longitudinal axis of said shaft, a knob attached to the end of said shaft projecting externally from said housing, four metal discs mounted on said shaft and re volvable therewith, insulating means mounted on said shaft adjacent the sides of said metal discs, a coil spring mounted on said shaft between one wall of said housing and the insulating means adjacent the disc disposed innermost toward the knob on said shaft, metal contact means attached to each of said four metal discs and movable therewith, four stationary metal contact brushes attached to the inner wall of said housing, each of said four stationary metal contact brushes adapted to contact individually and separately in wiping manner with one of the four said metal discs, a binding post attached to each of said stationary brush contact members and projecting through one wall of said housing, two of said binding posts adapted to facilitate connection with the primary circuit of a radioreceiving apparatus and two of said binding posts adapted to facilitate connection with the secondary circuit of a radio receiving set, a plurality of contact means mounted in the wall of said housing and projecting externally and internally therefrom, said contact means being arranged in groups of four, each of said contact means being adapted to contact individually and separately with one of the movable brush contact members attached to said metal discs, two of each of said group of four contact means adapted to facilitate connection with the primary circuit of a radio receiving coil of specified wave length receptivity and two of each group of four contact means adapted to facilitate connection with the secondary circuit of a radio receiving coil of specified wave length receptivity.

3. In a device of the class described, a housing of substantially rectangular shape, a revolvable shaft projecting through said nous ing and supported by the walls of said housing, one end of said shaft projecting externally from said housing, means for securing said shaft in spaced relation in said housing along the longitudinal axis of said shaft, a knob attached to the end of said shaft projecting externally from said housing, four metal discs mount-ed on said shaft and re Volvable therewith, insulating means mounted on said shaft adjacent the sides of said metal discs, a coil spring mounted on said shaft between one wall of said housing and the insulating means adjacent the disc disposed innermost toward the knob on said shaft, metal contact means attached to each of said four metal discs and movable therewith, four stationary metal contact brushes attached to the inner wall of said housing, each of said four stationary metal contact brushes adapted to contact individually and separately in wiping manner with one of the four said metal discs, a binding post attached to each of said stationary brush contact members and projecting through one wall of said housing, said binding posts adapted to facilitate connection with power means of a radio transmitting circuit, a pin rality of contact means mounted in the wall and internally therefrom, said contact means being arranged in groups of four, each member of said contactmeans arranged in groups of four being adapted to contact individually and separately with one of the movable brush contact members attached to said metal discs, and each group of four of said contact means adapted to facilitate connection with resistance units in a radio transmitting circuit.

4. A switch comprising a rotative shaft, a plurality of spaced apart discs on and rotatable with said shaft and insulated from each other, a plurality of groups of stationary con-- tacts and said groups being radially arranged about said shaft, the number of said contacts in each of said groups equaling the number of said discs, a group of stationary brush contacts each having constant wiping engagement with one of said discs, and a wiping contact carried by each of said discs, said last named contacts adapted to have selective engagement as a group with any one of said first named groups of contacts upon rotation of said shaft.

In testimony whereof I aflix my signature.

ANDREW BROSNATCH. 

